package com.http;

import java.io.IOException;
import java.io.InputStream;
import java.io.InterruptedIOException;
import java.io.UnsupportedEncodingException;
import java.net.UnknownHostException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.TimerTask;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

import javax.net.ssl.SSLException;
import javax.net.ssl.SSLHandshakeException;

import org.apache.commons.io.IOUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.http.HttpEntity;
import org.apache.http.HttpEntityEnclosingRequest;
import org.apache.http.HttpHost;
import org.apache.http.HttpRequest;
import org.apache.http.NameValuePair;
import org.apache.http.NoHttpResponseException;
import org.apache.http.client.HttpRequestRetryHandler;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.HttpRequestBase;
import org.apache.http.client.protocol.HttpClientContext;
import org.apache.http.config.Registry;
import org.apache.http.config.RegistryBuilder;
import org.apache.http.conn.ConnectTimeoutException;
import org.apache.http.conn.routing.HttpRoute;
import org.apache.http.conn.socket.ConnectionSocketFactory;
import org.apache.http.conn.socket.LayeredConnectionSocketFactory;
import org.apache.http.conn.socket.PlainConnectionSocketFactory;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.protocol.HttpContext;

import com.google.gson.Gson;
import com.google.gson.JsonObject;

public class HttpConnectionPoolUtil {
	private static Log logger = LogFactory.getLog(HttpConnectionPoolUtil.class);

	private static final int CONNECT_TIMEOUT = 10000;//设置从连接池获取连接实例的超时10s
	private static final int SOCKET_TIMEOUT = 10000;// 设置读取超时10s
	private static final int MAX_CONN = 10; // 最大连接数
	private static final int MAX_PRE_ROUTE = 10;// 默认的每个路由的最大连接数
	private static final int MAX_ROUTE = 10;// 设置到某个路由的最大连接数
	private static CloseableHttpClient httpClient; // 发送请求的客户端单例
	private static PoolingHttpClientConnectionManager manager; // 连接池管理类
	private static ScheduledExecutorService monitorExecutor;

	private final static Object syncLock = new Object(); // 相当于线程锁,用于线程安全

	/**
	 * 对http请求进行基本设置
	 * 
	 * @param httpRequestBase http请求
	 */
	private static void setRequestConfig(HttpRequestBase httpRequestBase) {
		RequestConfig requestConfig = RequestConfig.custom()
				.setConnectionRequestTimeout(CONNECT_TIMEOUT) // 设置从连接池获取连接实例的超时
				.setConnectTimeout(CONNECT_TIMEOUT)// 设置连接超时
				.setSocketTimeout(SOCKET_TIMEOUT) // 设置读取超时
				.build();

		httpRequestBase.setConfig(requestConfig);
	}

	public static CloseableHttpClient getHttpClient(String url) {
		String hostName = url.split("/")[2];
		System.out.println(hostName);
		int port = 80;
		if (hostName.contains(":")) {
			String[] args = hostName.split(":");
			hostName = args[0];
			port = Integer.parseInt(args[1]);
		}

		if (httpClient == null) {
			// 多线程下多个线程同时调用getHttpClient容易导致重复创建httpClient对象的问题,所以加上了同步锁
			synchronized (syncLock) {
				if (httpClient == null) {
					httpClient = createHttpClient(hostName, port);
					// 开启监控线程,对异常和空闲线程进行关闭
					monitorExecutor = Executors.newScheduledThreadPool(1);
					monitorExecutor.scheduleAtFixedRate(new TimerTask() {
						@Override
						public void run() {
							// 关闭异常连接
							manager.closeExpiredConnections();
							// 关闭30s空闲的连接
							manager.closeIdleConnections(30, TimeUnit.SECONDS);
							logger.info("close expired and idle for over 30s connection");
						}
					}, 20, 20, TimeUnit.SECONDS);
				}
			}
		}
		return httpClient;
	}

	/**
	 * 根据host和port构建httpclient实例
	 * 
	 * @param host 要访问的域名
	 * @param port 要访问的端口
	 * @return
	 */
	public static CloseableHttpClient createHttpClient(String host, int port) {
		ConnectionSocketFactory plainSocketFactory = PlainConnectionSocketFactory.getSocketFactory();
		LayeredConnectionSocketFactory sslSocketFactory = SSLConnectionSocketFactory.getSocketFactory();
		Registry<ConnectionSocketFactory> registry = RegistryBuilder.<ConnectionSocketFactory>create()
				.register("http", plainSocketFactory).register("https", sslSocketFactory).build();

		manager = new PoolingHttpClientConnectionManager(registry);
		// 设置连接参数
		manager.setMaxTotal(MAX_CONN); // 最大连接数
		// 默认的每个路由的最大连接数
		manager.setDefaultMaxPerRoute(MAX_PRE_ROUTE);

		HttpHost httpHost = new HttpHost(host, port);
		// 设置到某个路由的最大连接数，会覆盖defaultMaxPerRoute
		manager.setMaxPerRoute(new HttpRoute(httpHost), MAX_ROUTE);

		// 请求失败时,进行请求重试
		HttpRequestRetryHandler handler = new HttpRequestRetryHandler() {

			public boolean retryRequest(IOException e, int i, HttpContext httpContext) {
				if (i > 2) {
					// 重试超过2次,放弃请求
					logger.error("retry has more than 3 time, give up request");
					return false;
				}
				if (e instanceof NoHttpResponseException) {
					// 服务器没有响应,可能是服务器断开了连接,应该重试
					logger.error("receive no response from server, retry");
					return true;
				}
				if (e instanceof SSLHandshakeException) {
					// SSL握手异常
					logger.error("SSL hand shake exception");
					return false;
				}
				if (e instanceof InterruptedIOException) {
					// 超时
					logger.error("InterruptedIOException");
					return false;
				}
				if (e instanceof UnknownHostException) {
					// 服务器不可达
					logger.error("server host unknown");
					return false;
				}
				if (e instanceof ConnectTimeoutException) {
					// 连接超时
					logger.error("Connection Time out");
					return false;
				}
				if (e instanceof SSLException) {
					logger.error("SSLException");
					return false;
				}

				HttpClientContext context = HttpClientContext.adapt(httpContext);
				HttpRequest request = context.getRequest();
				if (!(request instanceof HttpEntityEnclosingRequest)) {
					// 如果请求不是关闭连接的请求
					return true;
				}
				return false;
			}

		};

		CloseableHttpClient client = HttpClients.custom().setConnectionManager(manager).setRetryHandler(handler)
				.build();
		return client;
	}

	/**
	 * 设置post请求的参数
	 * 
	 * @param httpPost
	 * @param params
	 */
	private static void setPostParams(HttpPost httpPost, Map<String, String> params) {
		List<NameValuePair> nvps = new ArrayList<NameValuePair>();
		Set<String> keys = params.keySet();
		for (String key : keys) {
			nvps.add(new BasicNameValuePair(key, params.get(key)));
		}
		try {
			httpPost.setEntity(new UrlEncodedFormEntity(nvps, "utf-8"));
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		}
	}

	public static String get(String url) {
		CloseableHttpClient httpClient = getHttpClient(url);
		HttpGet httpget = new HttpGet(url);
		String json = null;
		InputStream in = null;
		CloseableHttpResponse response = null;
		try {
			response = httpClient.execute(httpget);
			in = response.getEntity().getContent();
			json = IOUtils.toString(in);
		} catch (UnsupportedOperationException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			try {
				if (in != null)
					in.close();
				if (response != null)
					response.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		return json;
	}

	public static JsonObject post(String url, Map<String, String> params) {
		HttpPost httpPost = new HttpPost(url);
		setRequestConfig(httpPost);
		setPostParams(httpPost, params);
		CloseableHttpResponse response = null;
		InputStream in = null;
		JsonObject object = null;
		try {
			response = getHttpClient(url).execute(httpPost, HttpClientContext.create());
			HttpEntity entity = response.getEntity();
			if (entity != null) {
				in = entity.getContent();
				String result = IOUtils.toString(in, "utf-8");
				Gson gson = new Gson();
				object = gson.fromJson(result, JsonObject.class);
			}
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			try {
				if (in != null)
					in.close();
				if (response != null)
					response.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		return object;
	}

	/**
	 * 关闭连接池
	 */
	public static void closeConnectionPool() {
		try {
			httpClient.close();
			manager.close();
			monitorExecutor.shutdown();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
}
